Structure for reinforcement of building wall corners



- Sept. 16, 1958 J. G. STEMPLES STRUCTURE FOR REINFORCEMENT OF BUILDING WALL CORNERS 2 Sheets-Sheet 1 Filed May 20; 1953 INVENTOR JOHN G. 'STEMPLES I ATTORNEY Sept. 16, 1958 J. G. STEMPLYES 2,851,741

STRUCTURE FOR REINFORCEMENT OF BUILDING WALL CORNERS Filed May 20, 1955 Y Y 3 2 Sheets-Sheet 2 //V VEA/TOR JOHN G. STEMPLES United States Patent ()fihce STRUCTURE FOR REINFDRCEMENT OF BUILDING WALL CORNERS John G. Stemples, Highland Park, Ill., assignor to Powell Steel Lath Corporation, Franklin Park, ill., .a corporation of Illinois Application May 20, 1953, Serial No. 356,190

3 Claims. '(Cl. 20-4) This invention relates 10 a structure for the reinforcement of the corners of the walls of buildings, such as houses, and more particularly to the structure of a corner reinforcing strip for use on projecting or outside corners of interior Walls.

One of the objects of my invention is to provide a wall 2 corner reinforcing strip structure and amethod of applymg that strip to the corner of a dry wall structure, which reinforcing strip asapplied accomplishes the construction of a rugged and smoothly finished wall corner in only the two, general operations of applying the strip to the Wall Patented Sept. 16, 1958 5 terial within the bead which holds the strip in place.

which are such that it can be .firmly andquickly secured 3 inpla'ce without 'beingnailed to the wall structure.

V "Itf is a recognized fact that cornerre'inforcing strips which have holes in the flanges or along the corners, or both,.in orderto afford aholding coaction' with the adjacent cement 'or plaster material, cause undesirable depressi ons or un'evenness in 'the surface of the dried cement which covers them, =regardless ofthe fact that such cement or plaster was *'sm0oth"w hile wet. The covering of such depressions and the unevensurfaces requires, a second coat of plaster material or some added smoothing operation prior to finishing. The structureof my disclosed reinfforcingstrip presents a surface devoid of such holes and embodies other means for -securingit in place.

Also, when applied to a dry Wall by my disclosed method, a

the strip is hel'dfin' place.

Considered -more-specifically,-niy disclosed corner reinforcingstrip'embodiesfianges and a hollow corner bea'd integrally formed from stripmetal'stockwith the contours of-the interior of t'he bead and the structures 1andrelationships o-ft'he'fian'ges --calculat ed to force cementitious ma- -terial"into'the bead,-when 'th'ecorner reinforcing strip is -applied'toa wall corner in accordance with 'my disclosed 'method, and-which beadfis not only rigidifiedgand strengthened-by the cementitious material included therein, when "soldified, bu't'the internal-contours of which "beadare developed toprovide means for securely'holding .the strip in place'relativetoa wall corner when the cementitious material has become set.

t'herebetween smaller byifrorn 1" to '10 than the angle of the wall'corner' to which it is to be applied, and saidjflange .portionsbeingintegrallyadjoined through a formed hol- "lowbead of arcuate section and the arcuate extent of which is'such that the space within the hollow bead opens into the space between the flanges through a throat having a width no greater than the diameter of the-arcuatebead and no smaller than one-half of the said diameter, thereby smooth "finish plaster coat may be achieved by putting 45 such finish "coating directly 'over the 'cem'ent'by which Even more specifically stated, and although variations' may be made in the width of the throat between the angularly related flange portions and the hollow ,;arcuate bead of my described corner reinforcing strip without depart- 0 ing from the scope of this invention or eliminating the advantageous results securable therefrom, 'my preferred corner reinforcing strip structure has, a hollow arcuate bead and integral flange portions extending in angular relationship to one another from the bead with the saida'rcu- 5 ate bead and said flanges being so constructed and arranged that the inner surfaces of the flangeportions are in planes intersecting at substantially the geometric center of the arcuate bead and the width :of the open throat'at the intersection of the flange portions with the arcuate bead is approximately equal to the square root ,of two times the square of the radius of thearcuate bead.

Other objects and advantages of the invention will be apparent from the following descriptionand the accompanying drawings in which similar characters of refelcnfifl indicate similar parts throughout the several vie s.

Referring to the two sheets of drawings:

Fig. 1 is a fragmentary perspective view, witl i :parts shown in section, illustrating the structure of a Wall corner having the reinforcing strip of this invention applied thereto in accordance with my preferred method;.

Fig. 2 is atop sectional view of the structure illustrated in Fig. ,1, wherein the section is taken substantially as indicated by a line 2-2 and accompanying arrows ,in Fig. 1; V I I i Fig. 3 is an end view drawn to a larger scaleandshowing a preferred embodiment of my corner reinforcing strip;

Fig. 4 is a fragmentary perspective view depicting one preferred manner of applying cement to a wall corner preparatory to the mounting of my corner reinforcing strip in accordance with'one phase of my preferred method; a j

'Fig. 4a is atop view of a wall corner prepared in the manner depicted in Fig. 4 and which is ready tohave the corner reinforcing strip appliedvthereto;

Fig. 5 is a perspective view depicting an alternative method of applying-cement preparatoryto thernountingi of my corner reinforcing strip relative to a walls'tructure, and depicts the cement being applied to the internal sur- 0 faces of thecorner reinforcing strip;

Fig. 5a is a fragmentary perspective view drawn toa larger scale than Fig. '5 and illustratingin greater-detail the application of cement to one surface of rny corner reinforcing strip;

Fig. 6 is a fragmentary perspective view depicting one operation of my preferred method of mounting my disclosed corner reinforcing strip relative to the corner of a dry wall structure; 7 g v Fig. 7 is another fragmentary perspective view depict- 0 ing an additional step utilized in my preferred method for mounting and finishing a Wall corner embodying my reinforcing strip; and v Fig. 8 is a top sectional view, drawn to alargerscale f thaniFig. 7, wherein the section is taken substantially on 5 a line 88 of Fig. 7 and in the direction indicated by arrows.

In the exemplary embodiment of myinvention which V is depicted in the accompanying drawings for illustrative purposes, I have shown the structure and method of 0 application of a corner reinforcing strip ltl adaptedparticularly for use on dry wall structures .such $12 and securely mounted relative to the wall structure without the use of nails or other fastening elements. In the disclosed wall structure 12, wallboard panels 13 and 14, such as plaster board, are secured to building framework, such as a stud 15, by suitable fastening means, such as nails 16. As depicted in Figs. 1 and 2, the wallboard panels 13 and 14 abut adjacent one corner of the stud 15, so that the end surface of one panel is substantially, but not necessarily, flush with the outer face of the adjacent panel, thereby providing a substantially square wall corner surface. As is customary, such wall corner surfaces are desirably reinforced and finished by the application thereto of a corner reinforcing strip.

In accordance with this invention, I utilize a corner reinforcing strip which is integrally formed from strip sheet metal stock, such as steel, aluminum or zinc. When steel is used, the stock is preferably galvanized or otherwise suitably surface coated. When aluminum or zinc isutilized, it is preferably either knurled to provide a roughened surface, or etched chemically, as by treatment in a zinc phosphate solution. Such surfaces improve the adhesion between the strip and the cementitious materials utilized therewith in the wall structure.

My disclosed corner reinforcing strip is imperforate, since no holes are required for nails or in order to provide for the holding of cementitious material or plaster relative thereto. Furthermore, as has been mentioned, such holes in corner reinforcing strips now in use cause depressions or roughness in the cementitious material which require additional operations for the attainment of a smooth finish coat on the plaster covering the flanges of the strip. Further than this, my disclosed corner reinforcing strip embodies substantially fiat flange portions 17 and 18 which diverge angularly from one another and are integrally joined through a formed hollow bead 19, which bead is relatively small compared to the width of the flange portions and projects outwardly from the general planes of the flange portions.

Considered in greater detail, the hollow bead 19 of my disclosed corner reinforcing strip is practically arcuate in section and the flange portions 17 and 18 are adjoined to opposite sides thereof through relatively abrupt corners 20 and 22. Also, the planes of the inner surfaces of the flange portions are so disposed that they intersect internally of the hollow bead. Since it is contemplated that cementitious material will underlie my disclosed corner reinforcing strip and fill the hollow head 19 when the strip is mounted on a wall structure in accordance with my preferred method, the arcuate extent of the bead 19 and the angular disposition of the flange portions 17 and 18 are such that the internal Width or diameter of the bead 19 is greater than the width of a throat 23 between the corners 20 and 22. In order to provide for the entrapment of cementitious material within the hollow bead, which material will aid materially in securing the corner reinforcing strip in place relative to a wall structure, and also to provide ample strength in the cementitious material at the throat section for accomplishing the desired purpose, as well as to provide for the flow of cementitious material into the bead when the strip is mounted, the width at of the throat should not be greater than the diameter or width of the interior of the bead and should not be less than one-half of the internal diameter or width of the bead. In my preferred structure, the width a of the throat is substantially equal to the square root of two times the square of the radius of the interior of the bead. When the aforementioned proportions are utilized, it may be understood that after the cementitious material within the bead has set and become dried, such cementitious material would have to be sheared from opposite sides of the interior of the bead or would have to break at the throat in order that the reinforcing strip could be moved bodily away from the wall structure. It may also be observed that cementitious material underlying the flange portions 17 and 18 and within the bead 19 extends continuously along the full length of the reinforcing strip, as well as providing a hardened reinforcing core for the corner bead when the strip is installed.

To aid in the mounting of the disclosed COI'DEI' IfilII- forcing strip and to assist in the forcing of cementitious material into the interior of the hollow head 11 from between the flange portions 17 and 18 and the adjacent margins of the wall surfaces when the corner reinforcing strip is pressed cornerwise into place, the angle x between the flange portions 17 and 18 of my corner reinforcing strip is somewhat less than the angle formed by the wall surfaces to which the corner strip is to be applied. For application to a corner at which the wall surfaces are disposed in right-angular relationship, the angle x between the opposed internal surfaces of the flange portions 17 and 1B is not more than 90 degrees and preferably greater than degrees. In my preferred corner reinforcing strip I utilize an angle of approximately degrees. By utilizing this acute angular relationship between the flange portions 17 and 18 and pressing the corner reinforcement strip into place in a cornerwise direction, as depicted in Fig. 6, with a layer of cementitious material 24 between the inner flange surfaces and the adjacent wall margins, the outer edges of the flange portions 17 and 18 not only serve as guides, but tend to retain cementitious material within the corner reinforcing strip until the bead is filled, and also provide for the extrusion of excess material along those edges and into overlapping relationship with the outer margins of the strip.

In the application of my disclosed corner reinforcing strip to the corner of a wall structure, cementitious material in the nature of plaster may be applied in a relatively heavy coat to the marginal portions of the walls adjacent the corner, as shown in Figs. 4 and 4a, or to both of the internal flange surfaces of the corner reinforcing strip, as shown in Figs. 5 and 5a. In either instance, the amount of cementitious material is desirably sufi'icient to fill the interior of the bead, provide a complete coating between the internal flange surfaces, and also provide some excess to extrude along the free edges of the flanges. With the initial coating in place, as described, the corner reinforcing strip is placed in contact with the wall corner surface throughout its length and with the cementitious material interposed between the wall and the strip. Then, the reinforcing strip may be effectively pressed cornerwise .into place, as depicted in Fig. 6, by applying pressure along the exterior flange surfaces, as by moving the thumb and first finger of the hand along the flange surfaces as pressure is applied. This pressure forces the plastic cementitious material into the bead and effects the extrusion of the excess along the flange edges.

After the corner reinforcing strip has been thus applied to the corner of the wall structure, the outer surface of the bead 19 is used as a screed and the surface of the excess or extruded cementitious material is smoothed and feathered out to the wallboard surface by the use of a straight edge tool, such as a broadknife, as depicted in Fig. 7. This provides a smooth and tapered surface 25 along the corner margin, as depicted in Figs. 7 and 8. Time is then allowed for the initially used cementitious material to become set and at least partially dried. About twenty-four hours is usually allowed for this purpose. After the allowance of time for such setting and drying of the initially used cementitious material, a finish coating of plaster or the like is applied over the initial coat and in a quantity to fill the spaces and interstices in the initial coat and cover the flanges of the corner strip to the level of the projecting head, after which the finish coat is smoothed while using the head of the reinforcing strip as a screed and with a straight edge tool, such as a broadknife, which feathers the finish coat out to the surface of the wallboard. This provides a smooth finish coat 26, as shown in Figs. 1 and 2.

While I have illustrated a preferred embodiment of my invention, many modifications may be made without departing from the spirit of the invention, and I do not wish to be limited to the precise details of construction set forth, but desire to avail myself of all changes within the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. In a reinforced corner structure for dry walls wherein prefabricated wall boards abut to provide wall surfaces in right angular relationship, the combination comprising an imperforate metal reinforcing strip having wall surface engaging flanges diverging from one another at an angle of not more than 90 degrees and more than 80 degrees, said flanges being integrally joined through a formed hollow bead which projects outwardly of the included angle between the flanges, said flanges also having substantially straight outer edges, said hollow bead being adjoined to each of the flanges by abrupt comer bends forming an open throat of a width less than that of the interior of the bead and wider than half the interior width of the bead, and said reinforcing strip being secured in place relative to the wall surfaces by a layer of cementitious material interposed between the flanges and wall surfaces and extending into the hollow bead through said throat.

2. In a reinforced corner structure for dry walls as defined in claim 1, said layer of cementitious material increasing in thickness toward the bead between each flange and the Wall surface, and said bead being substantially filled with the cementitious material.

3. A corner reinforcing strip adapted to use on dry wall structures and to be held in place relative to such structures by cementitious material interposed between the internal surface of the strip and the wall surface, said corner reinforcing strip comprising an integrally formed and imperforate sheet metal piece having side flange portions in angular relationship to one another and adjoined through a hollow bead of rounded and smoothly curved section, the juncture of each side flange portion with the hollow bead being in the nature of a relatively abrupt bend defining a corner, and said flange portions and hollow bead being so relatively disposed that said corners are in opposed relationship and define a throat narrower than the interior of the bead and wider than half of the internal width of the bead and through which cementitious material in a plastic state can pass from the adjacent inner surfaces of the flange portions into the bead when the strip is applied to a wall corner, the internal surface of the strip being roughened so as to form an effective bond with ccmentitious material.

References Cited in the file of this patent UNITED STATES PATENTS 201,098 Darby Mar. 12, 1878 1,290,802 Tennison Jan. 7, 1919 1,804,564 McChesney May 12, 1931 2,090,588 Witsell Aug. 17, 1937 2,643,423 Brendel June 20, 1953 FOREIGN PATENTS 437,693 Great Britain Nov. 4, 1935 156,679 Switzerland Nov. 1, 1932 

